I was hoping to have a detailed post up today about the conditions where gmail presents the user with a “via” but time seems to have gotten away from me. But I can give you the conclusions. A via is presented to the user when you have a DKIM pass and the domain in the d= does not match the domain in the visible from address. In this case the interface shows via the d= domain. A via is...
The cult of SPF lives
Years ago, prior to the public discussions of Domain Keys, there was SPF as the solution to all our email authentication problems. SPF was going to let people do all sorts of things with email. The proponents even privately asserted that it would solve the spam problem. In essence, SPF was a cult. BoF sessions at meetings had the flavor of a big tent style revival. Those of us who didn’t...
SPF records: not really all that important
I’ve been working through some Hotmail issues with a client over the last few months. One of the things that has become clear to me is how little Hotmail actually does with SPF records. In fact, Hotmail completely ignored my client’s SPF record and continued to deliver email into the inbox. This isn’t just a sender that had a “well, we think most of our email will come...
ESPs, Non-portable Reputation and Vendor Lock-in
I’ve seen some mentions recently of ESPs suggesting that if you use your own domain in the From: of mail you send through an ESP then that ESP can’t “do email authentication” properly unless they require you to edit your domains DNS settings. That’s not really so, but there is a kernel of truth in there. The real situation is, unsurprisingly, a bit more complicated...
Who can you trust?
I’ve been recently dealing with a client who is looking at implementing authentication on their domains. He’s done a lot of background research into the schemes and has a relatively firm grasp on the issue. At this point we’re working out what policies he wants to set and how to correctly implement those policies. His questions were well informed for the most part. A few of them...
How to disable a domain
Sometimes you might want to make it clear that a domain isn’t valid for email. Perhaps it’s a domain or subdomain that’s just used for infrastructure, perhaps it’s a brand-specific domain you’re only using for a website. Or perhaps you’re a target for phishing and you’ve acquired some lookalike domains, either pre-emptively or after enforcement action...